The Cabineteer Writes About... Chisels.
Created | Updated Jan 17, 2013
The humble chisel is probably the most versatile of the tools. You can use it as an emergency straightedge, bevel-side down it is helpful in the removal of dried glue from the inside corners of a workpiece and, should all else fail, you can even employ it with a hammer or mallet in the removal of wood. In form, it consists of a steel blade where one surface is larger than its opposite to accommodate the bevelled edges on three sides, the important one being the short sharp one, the opposing short side tapers to a blunt point known as the tang, housed by the wooden or plastic shock-absorbing handle. When it is not dangling in its custom-made housing in the toolbox with a cover over the blade (see pic) it should always be pointing away from you or anybody else. When walking (never running) with it, always hold it as close to the blade as safely possible. Personally, I keep my thumb over the cutting bevel so if anything does happen the only damage is mine. If you leave it on the bench always make sure it is bevel-side down so the actual blade edge is above the bench surface, preventing the need for constant sharpening. When removing small shavings of wood such as the housing for a hinge, hold the blade down with one hand and the handle with the other in the same manner as you would a rifle with the butt of the handle in your shoulder providing the motive force. Sharpening is part art, part science. Once you have used a grindstone to grind the bevel to a 25° angle (keeping the blade wet and cooling it frequently by waving it about in a water bath) it is time to employ the oilstone at a 30° angle. While any type of mineral oil is usable the best, oddly, is baby oil. Just a few drops along the length of the stone are enough to provide a suspension medium for the steel shavings, which perform the actual sharpening duties. All the literature will tell you to use a figure-of-eight pattern for sharpening; this will have the effect of leaving a groove in your stone that will in turn make for an uneven edge to your blade. It will also shorten the life of your oilstone, as you will need to resurface it often. Personally I use a combination of small circles going around the edge into the centre along with a zigzag pattern using the entire width of the stone going from end to end in order to use as much of the surface as possible. Sharpening leaves you with a slight burr along the blade edge. You must remove this by getting stroppy. In other words using the suede side of a strip of leather known as a strop, preferably glued to a board for strength. You should pull the chisel back along the strop keeping it flat and alternating sides thereby folding the burr back & forth until it falls away. There is another method for sharpening that some of the top cabinetmakers (who do not own a water stone) use, which goes as follows. Once you have your 25° edge grab a sheet of 120-grit sandpaper and tape it to a pane of glass. Wet it slightly and rub the back of the blade (the larger of the two surfaces) over ever-finer grit paper until you achieve a ‘mirror surface’ on the leading inch of your chisel. Now do the same for the bevel until you reach the 600-grit level (some US cabinetmakers say 8000-grit) where you change the angle to 30° to polish your cutting edge. To remove your non-existent burr, wipe the palm of your hand off the alternating surfaces of your blade until it is gone. You will also be further sharpening the blade using your natural skin oils with this method. Whenever you actually use your chisel, wipe a little beeswax along the blade. This applies to any cutting surface that touches timber.
